#include <iostream>
#include <cstdio>
using namespace std;

int main()
{
    char c;
    int state=0;
    while((c=getchar())!='\n')
    {
        if((state==0&&c=='h')||
            (state==1&&c=='e')||
            ((state==2||state==3)&&c=='l')||
            (state==4&&c=='o'))
            state++;
    }
    if(state==5) cout<<"YES"<<endl;
    else cout<<"NO"<<endl;
    return 0;
}
